Tube splicing



also desirable here so that all cemented tubes will be spliced under uniform crcumstances.

I believe the main reason why this condi tion has not been understood in the past is because of the Igenerally made assumption that only a large or easily visible amount of bloom need be considered dangerous to the splice. I have found by my experiments, however, that it is important to have the cement contact as far as possible with the clean rubber surface as it comes from the buffer, before the latter has had a chance to accumulate any bloom.` The manner in which this result is assured with uniformity for all tubes will appear below.

Moisture between the rubber and the cement, or between the layers of cement on the overlapping portions of the spliced tube, will cause non-adhesion of adjacent rubber surfaces; and, if a steam cure is used in vulcanizinpr the splice. will cause blowing or blistering due to the rolatilization and consequent expansion of the moisture. The ac` cumulation of this moisture varies with the humiditv of the atmosphere and with the temperature of the tube. which may in the old processes be lower than the temperature of the atmosphere where the tubes are being cemented. l have found` however. that by followingr the process described below the moisture will not be permitted to form and a more uniformly good product will result.

In practice I tnd it convenient to combine the limitation of bloom and moisture in one stage, und to unite the steps taken for these purposes with others which will appear below. Before considering the preferred manner of carrying ont the process in detail its more general characteristics may be dismissed. Budino is generally accomplished byv pressing the surface to be treated against a rapidly revolving wire brush or other abrasive `wheel. This scratches or abrades the surface of the rubber so that all dirt and bloom is removed and :1 fresh surface of rubber is presented. 'lhe friction of this operation warms the tube at the point where it is lmll'ed, and this warming, together with the mechanical removal of the surface. eliminates any moisture from the butcd portion. If now the tube so prepared is cemented before it cools sullicicntly to permit moisture to condense on it` defects due to the presence of moisture between the rubber and cement will be eliminated. Fur thermore, if the cement is applied before the butled tube has had time to cool the danger of bloom will be elimiimted.r as no injurious bloominf Y can occur in so short a time, Ccmentinu' on thc warm rubber surfrc has also thc advantage of crt-,ating :i la cf adhesion between thc ccmcnt und :mi-lm. than tt the rubber were cold. lo dr; clfnuitcs,

or Where for any other reason the atmospheric humidity i's low, the time between the ufling and cementing need not be so short as to kee the tube warm when it is cemented, but still the time should bc so short as to permit no appreciable blooming of the rubber. I prefer, therefore, to -pass the tubes directly and successively from the buflingr to the cementing, so that all tubes will be treated the same and variations in the characterpof the splices due to production conditions will be avoided. For a similar reason, to avoid condensation of moisture on the cemented portion of the tubes before splicing. due to the cooling of the tube by evaporation of the cement, the cement is preferably dried whihl the tube is warmed and the tubes are delivered to the splicing operators successivelv and before they have had time to cool sufhciently to permit any accumulation of moisture.

A further difficulty experienced with tube splicing processes formerly in use was that there was, during the handling of the tubes at'ter ccmenting, an inevitable contact between cemented surfaces and between these surfaces and other objects. Even Where the precaution was taken of placing protective strips of holland cloth or other material between adjacent tubes, difficulty was experienced due to some of the filler with which the holland cloth is impregnated coming olf on the cement, causing lack of adhesion in the later formed splice, and to some of the cement being.,r pulled off by the cloth. Where contact of any kind occurs, whether between the several tubes or between the tubes and other objects such as the trucks or even the protective strips, some tubes will suffer (lue to the cement becoming separated or stripped from the rubber, and from dirt be'- ing deposited on the cement. This cause combined with the others mentioned to produce a large and fluctuating perccntucc ol' defective splices. In practicing thc method forming this invention I preferably avoid also these troubles by supportingr the tubcs throughout their treatment so that their ends will not be in danger of accidental coz:- tact with cach other or with other objects.

The manner in which these several hun turcs nrc carried out in the pructicul working* of thc invention will now be dcscribcd in connection with thc accompanying drawinns. in which` lug. l is a },iei spcct|vc view showing one A manner of practicing the invention: A Fig. 2 is a detail ot thc apparatus fibown m Eig. l; M

Fig. Cl is a detail illustrntilm' the boilingY of one end of a tube;

Fig. 4 is a similar detail showing' tht` buliingr of the other cud of the tubc:

Fig. ."r is :i detail showing thc ccmcnt'inor of onc cud of u tube;

l lo

Fig. G is a detail of the othei` end of the tube; and

Fig. i is a detail of the splice.

ln order to insure equal treatment f r lall tuiles ii. respect to time elapsed between successive operations,A thereby ull'ortlingr control of the im )orient time element is (liscufisetl above, :imi to hohl the tolles with their ends free and out of Contact, the tubes preferably sui'iported ami irioved through succefesive operations upon e moving: surface such :is a conveyor l0. This conveyor muy he el' any suitable coiietructioxi so es to Siu port the central portion of the tuiles ac permit the side portions to hang free. AS Shown the conveyor comprises belts or chains 11 (Fig. 2) having cross slats 12'coloredin sequence, as b, o, and Ll, for s. purpose to appear, The conveyor is supported hy pulleys '13 and is driven at e slow but steady rute of speed by a motor 14.A The pulleys 1? :ire supported' in a, suitable framework, amil suitable provision is made for supporting the upper mid lower runs of the conveyor het Ween the end pulleys, as is well understood hy those familiar with the insti-illation of conveyors. The lower run of the conveyor preferably passes through a housing-f 'l'scrvixig to protect it from the dropping: of ceiuent or hutl'efl-ol't' particles, li'itermediate ot' its length the top run ot the ronveyor paseos through :i chzuiher 16. lieiited es hy steam pipes i7 and provided with suitable ventileting devices indicated pgn-1 nerieally by 18. The mechanical structure of the decriheil apparatus muy he vari-cil widely, :is my invention relates vto the met of treating the tuhcis rather than to the (letilet'l apparatus for carrying `it out.

The tuiles nre placed on the conveyor ut the end to the left in Fig. l' in n. state ready for boiling. 'lviiey are therefore preferably trimmed to length. and Skived or beveled as indicated at if) (Fig. il) ,izilthougli the exact treatment prior to this point is not material. lllv the s-:tvmly 'irai-el of the conveyor tlv-se tuiles are lli-ought to opt-.rz1- tors 2f?. each o whom is' 'provided with a power driven boiling wheel 21, prefeeahly proviilcfl with the usual suction hoocl {not shown), )ie'eiul of the tuhe is cutleil or heut boel( on itself as i'mlioeitefl ut 22, so that the boiling :mtl ccmentingr will he tiene ou what is to he the iiisiiie the tulle, whihl the other mul ifi left Straight as; at The operators ou one Sitte of the conveyor operato on one rml of the tubes while those opposite work ou the other cnil,-

l have toiuul :i suitable speed for the m.'eyor to he in the neighborhood of si); feet per minuta although l (lo not limit myself to that ligure. lf thetxihes: are spat-eil about Si): inches apart they will pa-Ss along: taeter thun one mun could thoroughly huil' there. For this reason have shown three operators: on each side of the conveyor, who Work selectively on seperate tubes. For indieating to the workmen which tubes they are to take, use is made of the colored rross: shits b, c, and (l. By cach workmai'l taking; only the tubi-s on his particular color,` all the tuiles will he treated with ample time elloweel for each. i

The moi-'ement ot' the conveyor tot es the ,uhes individually and successively from he h: fing operators to operators 24. simi-A urly arranged on opposite sides of the con- -eyon who cement the ends of the tubes. rit'i-.raiilv in order to prevent the unde- :iireti application of cement to the body of the tulle, a protecting strip of holland clot-h or other Suitable meterial is inserted under thel turneol back. portion 22. The cement conveniently applied to the bu'erl poi-tiem` and 23 by a`brush 26. As` shown, thi-ee verruiming operators have been s1 etioned on each side of the conveyor, corresponding to the three helling operators 20. It. is generally pre fer-able to place two coats of. cement on the tubes, and in this case the first operator cements the tubes on slats b and c, the second operator those on sluts c and fl, and the third operator those on shits uml (Z.

From the verrichting operators the tubes are carried individually and successively through the drying; chamber 1G (showy tirol-.eri ewiv mul therefore not in ils full leugthi. (lo emerging from the 4far end of the drying chamber the .tubes-are ready for splitsing. Stationeil adjacent the conveyor :it this point cre Splicing operators 9.7, who from the conveyor the tubes on the proper colored slats and form the splice '28 (Fig. 7) in :my suitable manner, such for exnrn le es the method shown in the patent to I ari-leon, No. 1,3ll,392, dated July ee i919.

it will he seen that controlled time conditions are obtained in this manner by all tuiles., :mtl that, hy presenting the tubes individually eiul successively from one opl ao to the next throughoutvthe process "lciilties referreil to above will he illus described my invention, I

' i e methoii ot splicing rubber tubes, supporting o smell central length of' the tubes leaving the ends of' each tulle freely misguided, continuously moving: tho central portion of the tubo to control the sequence und frequency of the operations to be performer hulingr and cementing the ends of the tubos while temporarily arresting the emile hut.- xiot the middle of the tubeS.dry ing-:the cement while the tubes are still so susperuleii. :ind presenting the tubes successively for splicin 2. ln it metho of splicing rubber tubes,l

bufling the ends of the tubes on the surfaces which are to overlap when spliced, Supporting,r a small Central length of the tubes while leaving the ends of each tube freely suspended and out of Contact with each other, cemening the bulfed portions while so supported and successirelya'nd immediafely after the bufling, carryingthe cemented tubes while so supported through u drying chamber, and presenting the tubes in dividuallyand successively from the drying chamber for splicing. whereby controlled time conditions are maintained and formation of bloom on the bulfed portions is avoided.

' JOHN GRENNOR, JR. 

